body {
    margin: 0;
    padding: 0;
    font-family: Arial, serif;
}

.no_margin_padding {
    margin: 0;
    padding: 0;
}

.topmenu {
    background-color: #b1b0b0;
    margin: 0;
    padding: 0;
    position: fixed;
    top: 0;
    width: 100%;
    overflow: hidden;
    list-style-type: none;
}

.topmenu li {
    float: left;
}

.topmenu li a {
    display: inline-block;
    color: #3d3d3d;
    text-align: center;
    padding: 16px;
    text-decoration: none;
}

.topmenu li a.active {
    color: white;
    background-color: #930fe5;
    cursor: pointer;
}

.topmenu li a:hover:not(.active) {
    background-color: #222;
    cursor: pointer;
    color: white;
}

.clear_fix:after {
    clear: both;
    content: '';
}
/* 头部标题 */
.header {
    padding: 30px;
    text-align: center;
    background: white;
}

span{
    color: #66cc66;
}